Haematology p186 Flashcards
components of blood
plasma 55%
red blood cells 44%
WBCs, platelets 1%
plasma components
7-9% proteins
90% water
- 1% sugar
- 03% urea
- 9% salt
red blood cells
carry oxygen and Hb
release ATP which cause vessel walls to relax to promote blood flow
when lysed pathogenically by bacteria the Hb in the RBC produces free radicals which break down the bacterial cell membrane destroying it
anaemia is
reduction of Hb in blood (not necessarily red cells)
- red cell reduction is indicative of marrow failure
anaemic pt have below average Hb
av male Hb
13.5-17.5g/dl
anaemia male - <13g/dl
av female Hb
12.0-15.5d/dl
anamic female 11.5g/dl
general clinical features of anamia
hypoxia - compensatory changes = inc HR + SV = CO
pallor - due to vascular constriction in skin
fatigue
tachycardia (to try and make up for poor oxygen transport)
may develop a murmur
in elderly it can manifest as palpitations, dyspnoea, angina and signs of caridac failure
histological classifications of anaemia
hypochromic microcytic (pale small cells)
- iron def, thalassaemia, some chronic disease
normochromic normocytic (normal colour, normal size)
- chronic disease (heart failure, renal failure), acute blood loss
macrocytic (large cells)
- megaloblastic (B12, folate), aplastic, liver disease
classes of anaemia
haematinic deficiency anaemias
haemaglobinopathy anaemias (globin chains)
marrow failure anaemias (reduced RBC)
3 marrow failure anaemias
aplastic anaemia
acute leukaemia (neoplastic proliferation of leukocytes, usually disseminated)
lymphoma (neoplastic proliferation of leuokcytes, usually solid tumour)
2 haemoglobinopathy anaemias
thalassaemia
sickle cell anaemia
haematinic deficiency anaemia (2)
iron deficiency anaemia
perncious (B12) megaloblastic (B9/folate) anaemias (def B12 and folic acid)
iron def anaemia
Causes include chronic blood loss, malabsorption of iron (coeliac disease), dietary deficiency, increased physiological demand (e.g pregnancy, puberty), Low ferritin (stores and releases iron)
Clinical features include
- Kolinychia (concave nails)
- Pruritus (itching)
- Angular Stomatitis
- Painless glossitis (beefy tongue)
Low Hb, Low MCV + MCH
pernicious megaloblastic anaemias
def B12 and folic acid
Both B12 and Folic acid needed for DNA synthesis in maturing erythroblasts
- Def. in either causes erythroblasts to have large nuclei= megaloblasts in marrow
B12 absorbed by intrinsic factor in terminal ileum
Folate absorbed in the duodenum
Clinical features include
- Painful glossitis
- Demyelination of the spinal cord
- Peripheral neuropathy
- Ataxia
Low Hb, High MCV
Thalassaemia
Normal Hb production
Genetic mutation of globin chains
- α chains (Asian)
- β chains (Mediterranean)
Clinical features include
- Chronic Anaemia
- Marrow Hyperplasia
- Spenomegaly
- Cirrhosis
- Gallstones
Treated w/ blood transfusions
Prevent iron overload
sickle cell anaemia
β chain substitution
Changes shape in hypoxic environment (prevents passage of cells through capillaries)
Heterozygous- Sickle cell TRAIT
Homozygous- Sickle Cell DISEASE
Clinical features include
- Vascular Occlusion
- Retinal Ischaemia
- Acute chest syndrome
aplastic anaemia
Diminished or absent Haematopoetic precursors in bone marrow
Present as, Pancytopenia, Macrocytosis (inc. MCV), reticulocytopenia (immature RBCs)
acute leukaemia
Accumulation of malignant white cells in bone marrow and blood
Malignant cells tend to be precursors (blast cells)
Two types Acute MYELOID leukamia and Acute LYMPHOBLASTIC leuakaemia
Neutropenic- ROU
Thrombocytopenia- Mucosal Bruising, Petechiae, epistaxis (nosebleed) and Gingival Hypertrophy
lymphoma
Malignant lymphocytes accumulating in Lymph nodes
- Lymphadenopathy, Peripheral vasculature, even organs
Nodular Lymphocyte-predominant Hodgkin’s Lymphoma (NLPHL) - malignant B cells lying in a meshwork of folicular dendritic cells and reactive lymphocytes
Classical Hodgkin’s Lymphoma- neoplastic B cells amongst Reed-Sternberg (RS) cells and plasma cells + eosinophils
Presence of RS cells determines whether it is a Hodgkin’s or Non-Hodgkin’s Lymphoma
normal RCC
male
4.7-6.1 million cells/mcL
usually normal in anaemia
check if normochromic/cytic
normal RCC
females
4.2-5.4 million cells/mcL
usually normal in anaemia
check if normochromic/cytic
WCC normal
between 4.5 and 10.0 thousand cells/mcL
MCV is
mean corpuscular volume (volume RBC’s take up, a.k.a size)
normal MCV
87 +/- 5 femtolitres (fL)
will be normal in bleeding but reduced volume overall
HCT is
haematocrite
% vol of RBC in blood
HCT in newborns
60%
0.6
varies in children
HCT in males
40-52%
0.4-0.52
HCT in females
46%
0.46
can be reduced in pregnancy
PLT is
platelets
normal PLT
150-400 thousand per mcL
ferritin in males
18-270mcg/L
ferritin in females
18-160mcg/L
polycythaemia
raised Hb
leukocytosis
raised WCC
thrombocythaemia
raised PLT
reasons for needing a blood transfusions
When one or more components of the blood has to be replaced quickly, i.e in blood loss
- e.g RBCs, PLTs, Clotting factors
When bone marrow can’t produce blood cells
- e.g RBCs, PLTs
if have only just one odd number in bloods
if multiple
reactive change?
more likely pre neoplastic - investigate
how to blood transfuse
Sample taken from patient
- ABO compatability
- Rhesus +ve or -ve
- Sometimes there are unknown antigens present
Tested v donated sample, if matched = given to patient
If poor match- fever, jaundice, fluid overload
Prion Disease- neurogenerative conditions
Bacteria (Syphilis) and Viruses (Hep B, C, HIV and TT viruses) can all be transmitted via transfusion of blood
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porphirins are
proteins involved in Hb metabolism
2 main types of porphyria
hepatic porphyria
erythropoetic porphyria
acute episodes of porphyria cause
purple urine, abdominal pain, seizures, skin rash from sunlight and psychosis
clotting factor VII def is
haemophilia A
X chromosome recessive inherited bleeding disorder (higher male incidence)
clotting factor IX deficiency is
haemophillia B (christmas disease)
mutaration of FIX gene on the X chromosome
results in low/absent level of FIX gene in plasma
severtity of haemophilia A correlates to
level of Factor VIII in blood
DDAVP is
desmopressin
can be usde to tx mild haemophilia and vWD by stimulating release of vWF
Von Williebrand’s disease
vWD
decrease in von Williebrand’s factor which causes a reduced factor VIII level
vWF acts as a carrier molecule for Factor VIII hence why it can’t be degraded to be used in coagulation as it isn’t near the site of insult
reduced platelet aggregation
3 acquired bleeding disorders
disseminated intravascular coagulation DIC
vit K deficiency
hepatopathology
disseminated intravascular coagulation
Consumption of clotting factors widespread
Causes microthrombi to form
excess consumption of factors and platelets means intial coagulopathy then excess bleeding
vit k def due to
malabsorption in GIT
hepatopathology causes
reduced level of clottisng factors produced so bleeding disorder
acquired platelet disorders
Thrombocytopaenic disorders
- Acute Idiopathic Purpura (Children)
- following a viral infection
- autoantibodies bind to platelets and cause them to be removed from circulation and destroyed by spleen
- Myeloproliferative disorders
- Bone marrow doesn’t produce enough platelets causing systemic low platelet count
Acquired disorders of platelet function
- Antiplatelet agents
antiplatlet agents
Aspirin inhibits Cyclo-oxygenase enzyme which is needed to synthesise thromboxane a2 which is needed to activate platelets
Heparin
Penicillins
hypercoagulation called
thrombophilia
heriditary thrombophilia
factor V Leiden mutation
protein C
protein S
anti-thrombin III def
acquired thrombophilia
antiphospholipid syndrome (Hughs syndrome)
caused by presence of Lupus anti-coagulant in blood
sugery, trauma, immobilisation, cancer etc
increased platelets called
thrombocythaemia
essential throbocytosis
inc platelets
v uncommon
managed with aspirin
INR is
internal normalised ratio
prothrombin time
Ratio of patients clotting value over the normal clotting value
Normal INR- = 1.0
Warfarin INR- 2.0-3.0
-
people who have AF or leg/lung clots have higher INR ratio
LOWER THE INR THE FASTER THE CLOTTING TIME
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